Heretofore, there has been proposed a vehicle travel control apparatus for determining the intention of a driver to adjust the vehicle speed of a vehicle based on the depression of an accelerator pedal, which is caused by the driver against a reaction force applied to the accelerator pedal. See, Japanese Laid-Open Patent Publication No. 2009-262846 (hereinafter referred to as “JP2009-262846A”).
According to JP2009-262846A, if the present vehicle speed of a moving vehicle is higher than a recommended speed that is estimated by a navigation system, then the vehicle travel control apparatus increases the reaction force applied to the accelerator pedal in order to bring the vehicle speed to the recommended speed.
The vehicle travel control apparatus also determines the driver's intention to accelerate the vehicle, the driver's intention to decelerate the vehicle, the driver's intention to maintain the recommended speed, or the driver's intention to maintain the present vehicle speed, depending on the depression of the accelerator pedal, which is caused by the driver with respect to the increased reaction force.
The vehicle travel control apparatus disclosed in JP2009-262846A is able to appropriately control driving of the vehicle depending on the intention of the driver to adjust the vehicle speed.
There also is known a vehicle travel control apparatus for assisting a driver of a vehicle in driving the vehicle by applying a reaction force to the accelerator pedal with an actuator such as a motor or the like. See, Japanese Laid-Open Patent Publication No. 04-236699 (hereinafter referred to as “JP04-236699A”) and Japanese Laid-Open Patent Publication No. 2007-022238 (hereinafter referred to as “JP2007-022238A”).
JP04-236699A discloses a technique in which, based on information of a curved road (21) from a navigation system (22), an approaching speed is calculated depending on road characteristics such as the radius of curvature of the curved road. Further, if the actual speed of the vehicle is higher than the approaching speed, the driver is informed accordingly and the driver is instructed to reduce the vehicle speed or to automatically decelerate the vehicle (see Abstract).
According to JP2007-022238A, if while traveling straight the vehicle sees a decreasing distance to a leading vehicle (200), which is detected by a laser radar (10), the vehicle travel control apparatus automatically brakes the vehicle (see, for example, FIGS. 1, 3, 4 and 7).